Solve the system of equations. $\begin{aligned} & 12x-5y = -20 \\\\ & y=x+4 \end{aligned}$ $ x=$
Explanation: We are given that $ y = {x+4}$. Let's substitute this expression into the first equation and solve for $x$ as follows: $\begin{aligned} 12x-5{y}&=-20\\\\ 12x-5\cdot({x+4})&=-20\\\\ 12x-5x-20& = -20\\\\ 7x&=0\\\\ x&=0 \end{aligned}$ Since we now know that $ x={0}$, we can substitute this value into the second equation to solve for $y$ as follows: $\begin{aligned} y &= {x}+4 \\\\ y&={0}+4\\\\ y&=4 \end{aligned}$ This is the solution of the system: $\begin{aligned} &x = 0 \\\\ &y=4 \end{aligned}$